LOL, if the packet has already hit the WAN of the router, the router can NAT 800+mbps, are you telling me that you believe that the router could possibly create a bottleneck there?
Once the packet is already at therouter the ISP has offered it to you as fast as then can. (respectively)If the packets are at the router, then the router can offer them to you faster then the ISP can get it to the router.
(ISP = 10-15mbps < Router = 800+mpbs.)
So now the issue is when the router is pulling from more then 1 source, (e.g. a UDP video stream [youtube] and a data source [FTP download]) how does it negotiate with both sources? Well the issue is still the same.
(ISP = 10-15mbps < Router = 800+mpbs.)
So for downstream QoS the router would have to negotiate with the ISPs hardware to request the packets in the desired order. We ALL know thats not going to happen.